The present invention generally relates to architectural lighting, and more particularly relates to luminaires that provide both direct and indirect lighting, so called "direct-indirect" luminaires. The present invention finds particular application in the field of linear fluorescent lighting where ambient light is produced from fluorescent lamps mounted in an elongated housing having a predetermined length and characteristic cross-sectional shape.
Linear direct-indirect fluorescent lighting has been known for many years. Such fixtures normally provide indirect or "up" lighting through the top of the luminaire housing which is open (or is covered by a light transmitting element such as a lens cover), and a direct or "down" lighting component through one or more openings in the bottom of the housing, openings which are typically covered by lenses, baffles, or louvers to shield the luminaire's fluorescent lamps from direct view at high viewing angles. In many such fixtures, the available light output from a direct-indirect luminaire mostly escapes as indirect light through the top opening of the luminaire housing while only a fraction of the available source light contributes to the down lighting. Other than shielding the light source, there is relatively little control over the down light component of the fixture. The present invention overcomes these disadvantages by providing a direct-indirect luminaire which greatly increases the control of the down light component of the luminaire and which permits a lighting designer to increase the amount of down light in relation to the luminaire's total available light output.